Recent content by Bigfoots mum

Now then, I am close to shedding a tear with this one. This integral has been popping up in a few electromag examples iv been doing and i have absolutely no idea what's going on here. The integral is 1/[(x2+z2)3/2] with respect to x According to the textbook the answer is...

No its not, my question is why is this integral equal to the quoted answer. I gave my attempt at the answer, which is nothing like the actual answer. I am baffled.

Iv used a computer, and it tells me its correct! Otherwise, yes i would have done as you said.

Now then, I am close to shedding a tear with this one. This integral has been popping up in a few electromag examples iv been doing and i have absolutely no idea what's going on here. The integral is 1/[(x2+z2)3/2] with respect to x According to the textbook the answer is x/[z2(x2+z2)1/2]...

Im having some four-vector definition issues. I have a relativity exam coming up and they quite often ask about 4-vectors. 1) Does this definition sound ok? 'A four-vector is 4 numbers, say X=(X0, X1, X2, X3), used to describe an event in minkowski space. The 'zeroth' is the time component...

Thanks muchly mapes, i was getting the old knickers in a twist for no reason there.

Iv made this question sound more complicated than it really is, haven't I?! Since its a closed cycle i presume there is no net change in the working substance after the cycle, and therefore the entropy change in the substance is zero?

I know its a state variable, hence my reasoning for part 1). Im not sure what your hinting at to be honest. Part 2) has me confused, mainly due to the fact its talking about the working subtance itself, and not a 'system', and how to reason for part 2).

Now then, a past paper question worth 3 marks. What is the entropy change of a working substance taken around 1) a completely reversible closed cycle and 2) a closed cycle containing irreversible steps? Explain your reasoning. Now this question has me a tad confused. I think that for part...

I used Kinetic Energy T = E - mc^2 where E is the total particle energy and mc^2 is the rest energy. Therefore gamma is 2, and we're away with the mixer. I just wasnt sure if this method would apply in the CM frame, but then I am not sure why it wouldnt! Thanks for the response

Now then, this is a past paper question for only 3 marks but its annoying me. 2 identical spheres undergoing an elastic relativistic collision. The spheres move with a speed such that their CM frame kinetic energy is equal to their rest energy. Calculate the speed the spheres in the CM...

Hi, i just want to check my reasoning on this problem. A working substance is taken around a closed cycle that involves performing some external work. It absorbes heat Q1 = 1000J from a resevoir at T1 = 1000K, and heat Q2 = 2000J from a resevoir at T2 =2000K. The only other exchange of heat...